3-amino-1h-pyrazolo(3,4-b)pyridines

ABSTRACT

IN WHICH Z1 stands for an optionally substituted alkyl or aralkyl group, K for the radical of a coupling component and A for an anion, and X, Y and Z are defined as further above. These dyestuffs, which are especially suitable for dyeing polyacrylonitrile, have a high tinctorial strength and generally afford good fastness properties.   WHEREIN X is amino, alkylamino with 1 - 6 carbon atoms, lower alkoxy- lower alkylamino, hydroxy- lower alkylamino, amino- lower alkylamino, di-lower alkylamino - lower alkylamino, cyclohexylamino, benzylamino, furfurylamino, pyridylamino, pyridylmethylamino, phenylamino, lower alkoxy-phenylamino, dilower alkylamino, di-hydroxy lower alkylamino, lower alkyl hydroxy lower alkylamino, lower alkyl phenylamino, hydroxy lower alkyl cyclohexylamino, hydroxy lower alkyl lower alkoxyamino, lower alkyl lower alkoxyamino, morpholyl, piperidyl, N- lower alkyl piperazinyl, pyrrolidinyl, morpholyl- lower alkylamino; hydrazino, lower alkylhydrazino, di-lower alkylhydrazino, trilower alkylhydrazino, phenylhydrazino, N-piperidylamino, Nmorpholyalmino, N-pyrrolidinylamino,- lower alkoxy, lower alkoxy - lower alkoxy, cyclohexyloxy, phenoxy, benzyloxy, hydroxy lower alkoxy; lower alkylthio, phenylthio; Y is hydrogen, lower alkyl, hydroxy -lower alkyl, di-lower alkylamino -lower alkyl, cyclohexyl, benzyl, phenyl, chlorophenyl, furyl, pyridyl-methyl and Z is hydrogen or lower alkyl and &#39;&#39;&#39;&#39;lower&#39;&#39;&#39;&#39; means groups with one to four carbon atoms. These compounds are valuable intermediate products for the preparation of dyestuffs, especially of azo dyestuffs of the formula   A 3-amino-1H-pyrazolo(3,4-b)pyridine of the formula

United States Patent 91 Fleckenstein et al.

[ Mar. 18, 1975 3-AMINO- l H-PYRAZOLO( 3,4-B )PYRIDINES [75] Inventors:Erwin Fleckenstein, Hofheim,

Taunus; Reinhard Mohr, Offenbach, Main, Germany [73] Assignee: HoechstAktiengesellschaft, Frankfurt, Main, Germany [22] Filed: June 26, 1973[21] Appl. No.: 373,766

[30] Foreign Application Priority Data June 30, l972 Germany 2232038 52us. Cl ..260/296 H, 260/2475 B, 260/268 BC, 260/293.6, 260/294.8 c,260/2949, 8/177 511 Int. Cl 0070 31/42 [58] Field of Search 260/296 H [56] References Cited UNITED STATES PATENTS 3,733,328 5/1973 Hoehn et al.260/2936 Primary E.\'aminer-Alan L. Rotman Atmrm'y, Agent, orFirm-Connolly & Hutz l57| ABSTRACT A 3-amino-lH-pyrazolo[3,4-blpyridineof the formula HFNHB N wherein X is amino, alkylamino with l 6 carbonatoms, lower alkoxylower alkylamino, hydroxylower alkylamino, aminoloweralkylamino, di-lower "lower alkylamino -lower alkyl, cyclohexyl, benzyl,

phenyl, chlorophenyl, furyl, pyridyl-methyl and Z is hydrogen or loweralkyl and lower means groups with one to four carbon atoms.

These compounds are valuable intermediate products for the preparationof dyestuffs, especially of azo dyestuffs of the in which Z stands foran optionally substituted alkyl or aralkyl group, K for the radical of acoupling component and A for an anion, and X, Y and Z are defined asfurther above. These dyestuffs, which are especially suitable for dyeingpolyacrylonitrile, have a high tinctorial strength and generally affordgood fastness properties.

6 Claims, N0 Drawings formula 1 3-AMINO-lH-PYRAZOLO(3,4-B)PYRIDINES Thepresent invention relates to novel 3-amino-1H- pyrazolo-[3,4,-b]pyridines of the formula 1 x N N/ Hal 1 in which Y is defined as aboveand Hal stands for a chlorine or bromine atom, with ammonia, a primaryor secondary amine, a hydrazine, a hydroxylamine, a hydroxy or thiocompound and condensing the soobtained compound of the formula [11 X Halin which X, Y and Hal are defined as above, with a hydrazine of theformula IV 1 Z NHNH IV.

The compounds of the formula 11 are reacted with the amines, hydrazines,hydroxylamines, hydroxy or thio compounds at about to 100C, preferablyat about 60 to 80C, advantageously in an inert solvent, for example in alower aliphatic alcohol having 1 to 4 carbon atoms. The reaction mayalso be carried out in an excess amount ofthe amine, hydrazine orhydroxylamine or of the hydroxy or thio compound as a solvent. Theexchange of the halogen atom in 6 position is ascertained by theanalysis of the NMR spectrum of the compounds of the formula 111.

The compounds of the formula 111 are condensed with hydrazine at about70 to 150C, preferably at about 100 to 130C, in an aqueous oraqueousalcoholic medium.

Starting from the compounds of the formula II, the novel compounds maybe prepared in a two-step process or also withoutintermediate'isolation.

The compounds of the formula 1 may also be available in their tautomericformulae, for example as compounds ofthe formulae V, VI or V11phenoxy-ethylamine, n-

Z 7 (VII) in which X, Y and Z are defined as above.

The 2,6-dihalogeno-3-cyano-pyridines of the formula 11, usedas startingcompounds, may be obtained according to known methods, for example byreacting the corresponding 2,6-dihydroxy-3-cyano-pyridines withhalogenating agents, such as phosphoroxy chloride, phosphoruspentachloride or phosphorus pentabromide (cf. J. org. Chem. 25,560/1960) or by reacting the corresponding l-alkyl-2-hydroxy-6-pyridoneswith halogenating agents (cf. German Offenlegungsschrift No. 2,049,831).

As starting compounds of the formula 11, there are,

for example, used 2,6-dichloroor 2,6-dibron1o-3- cyano-pyridines whichmay carry, in 4 position, an optionally substituted alkyl group, forexample the methyl, ethyl, propyl, butyl, hexyl, 2-dialkylaminoethyl,2-morpholino-ethyl, 2-aryloxy-ethyl, 3-alkoxypropyl, benzyl orpyridyl-methyl group, or an optionally substituted aryl group, forexample the phenyl, halogeno-phenyl, alkyl-phenyl or alkoxy-phenylgroup,

a cycloalkyl group, for example the cyclohexyl group,

or a heterocyclic radical, for example the pyridyl, thiazolyl or furylradical.

As primary and secondary amines, there are mentioned aliphatic,cycloaliphatic, araliphatic, aromatic and heterocyclic amines. Suitableprimary amines are, for example, ammonia, methylamine, ethylamine, 2-hydroxy-ethylamine, 2-methoxy-ethylamine, 3- and iso-propylamine, 3-hydroxy-, 3-methoxyand 3-isopropoxy-propylamine, 3-cyanopropylamine,allylamine, lor 2-methyl allylamine, n-, iso-, sec.- andtert:-butylamine, 2-amino- 2-methyl-propanol-( 1), crotylamine,3-amino-pentane, nand iso-amylamine, aniline, methyland methoxyanilines,dimethyl-anilines, amino-naphthalenes, N,N- diethyl-ethylene diamine,N,N-dimethylor N,N-diethyl-propylene diamine-(1,3). As secondary amines,there are, for example, mentioned dimethylamine, diethylamine,N-(2-cyano-ethyl)-N-(2-hydroxy-ethyl)- amine,N-di-(2-hydroxyethyl)-amine N-di-(2-cyanoethyl)-amine, N-methyl-,N-isopropyl-, N-n-butyl-, N- cyclohexylandN-benzyl-(Z-hydroxyethyl)-amine, di-nand di-iso-propylamine, di-nanddiisobutylamine, di-n-amyland di-n-hexylamine, morpholine, pyrrolidine,piperidine, N-methyl-piperazine, N-methyland N-ethyl-cyclohexyl-amine,N-methylbenzylamine, N-methyl-3-methyl-benzylamine, N-

phenyl-hydrazine, N-amino-pyrrolidine, N-aminopiperidine,N-amino-piperazine and N-aminomorpholine.

As hydroxylamino compounds, there are, for example, mentionedhydroxylamine, hydroxylamino-methyl ether, hydroxylamino-ethyl ether,hydroxylaminopropyl ether or hydroxyaminobutyl ether and the N- alkylderivatives thereof.

As hydroxy or thio compounds, there are used aliphatic, araliphatic,cycloaliphatic, aromatic and heterocyclic compounds, for examplealiphatic alcohols having 1 to 8 carbon atoms, alkylene glycols and theethers thereof, cyclohexanols, phenylalkyl alcohols, phenols,dihydroxy-benzenes and the monoethers thereof, naphthols, aliphaticmercaptans, thiophenols and heterocyclic hydroxy compounds.

As hydrazines of the formula N, there are used bydrazine andmonoalkyl-hydrazine, such as N-methyl-, N-ethylor N-propyl-hydrazine.

The compounds of the invention are valuable intermediate products forthe preparation of dyestuffs, especially of azo dyestuffs of the formulaVlll (VIII) EXAMPLE 1 93.5 Parts of2,6-dichloro-3-cyano-4-methyl-pyridine were heated at the boil in 300parts by volume of ethanol and, within 1 hour, 80 parts of diethylaminewere added. The temperature was maintained for 2 hours, the solution wascooled, the colorless crystallized precipitate was suction-filtered,thoroughly washed with water and the moist product was then placed in aflask having a capacity of 500 parts by volume. After addition of 150parts of glycol and 50 parts of hydrazine hydrate (of 80% strength), thecontents were refluxed for 3 hours. The solution was then cooled, 200parts of ice water were added and the crystallized precipitate wassuction-filtered. The compound of the formula Ulla was obtained in analmost quantitative yield and was purified by recrystallization fromisopropanol. Analysis: C H N calculated: 31.9% N found: 31.5% N

EXAMPLE 2 93.5 Parts of 2,6-dichloro-3-cyano-4-methyl-pyridine weredissolved in 400 parts of methanol and 27 parts of sodium methylate in200 parts of methanol were added .in such a manner that the temperaturedid not exceed 50C. After this addition, stirring was continued for 6hours at 50C, the mixture was cooled, ice water was added to thesolution and the precipitate was suction-filtered. The moist product wasdissolved in 150 parts of ethylene glycol, 50 parts of hydrazine hydratewere added and the mixture was heated at the boil for 3 hours.Subsequently, the mixture was cooled, ice water was added, thecrystallized precipitate was suction-filtered, thoroughly washed withwater and dried. The compound of the formula (IJHa OTENH: orno- N Nfiwas obtained in a high yield and could be recrystallized from ethanol. 1

Analysis: C H N O calculated: 31.5% N found: 31.3% N

EXAMPLE 3 was obtained in a high yield. Analysis; C H N calculated:47.2% N found: 46.8% N

EXAMPLE 4 Ulla ITE

EXAMPLE 5 was obtained in an almost quantitative yield. Analysis: C l-lN S calculated: 23.7% N found: 23.7% N

EXAMPLE 6 5 37.4 Parts of 2,6-dichloro-3cyano-4-methyl-pyridine 37.4Parts of2,6-dichloro-3-cyano-4-methyl-pyridine were heated to 100C for12 hours in an autoclave in were dissolved in 200 parts of methanol anda solution 200 parts of alcohol and 20 parts of methylamine. The of 18parts of n-butyl-mercaptan and 10.8 parts of somixture was stirred ontoice water, the precipitate was dium methylate in 100 parts of methanolwas added in suction-filtered, thorougly washed with water ahd such amanner that the temperature did not exceed 0 heated at the boil for 2hours with 100 parts ofhydra- 40C. Stirring was continued for 3 hours atthis temperzine hydrate. The solution was then cooled, diluted ature,the mixture was poured on ice water and the prewith water and thecolorless crystallized precipitate was cipitated oil was separated bydecanting. The oily phase suction-filtered. The compound of the washeated at the boil for 1 hour in 100 parts of ethylene glycol and 30parts of hydrazine hydrate. The mix- I5 011 ture was cooled, thesolution was poured on ice water, the separated precipitate wassuction-filtered and *F dried. The compound of the formula L,

OlIaNII 20 N NlI om NH could be purified by recrystallization fromisopropanol. Analysis: C H N calculated: 39.5% N found: 39.1% N A Thefollowing Table comprises compounds of the N NH 25 formula I:

TABLE Percentage ol' Empirical X Y Z formula N calcd. N found NH2 CH3 H.0 H N 42. n 42. a NHCuHn CH3 II Cid-1 71 15 28. 2 2S. 0 NHC2 5 CH: HCnH13N5 36.7 36.0 NI-IC3H1 OH; H CmH15N5 34. 1 33. a NHC4H9 OH: H CuHnNs32. 0 31. 4 OH; H 013mm. 28. 6 2s. 5 NH H CH 1! c 1r 5 2 2 NHCH 3 7 7 THCH3 II C|QIII3N5O 28.8 123.5 -NlI-OII2LO CH3 l[ CralluNs 33. 1 32. 7NlI-CH.-fl

on 1r 0 u o 2 2r." N1-r oom a 6 0 7 -NH CH3 II (3131 l'laNs 29. 3 28. .l

U: H H CyzlIuNu 35.0 34.4 -NlI L NHC3H1(iso) OH; H o H N 34.1 33. 9 NH(CHzhO CH3 CH; 11 CiiHiiNiO 29. 7 29. s /CI'I3 CH3 II CmHgoN 33. l) 33.4 -NII(CIIQ)B N -Ni[-01ncrI2-01t 0m ll on! lIlNfiU as. a 33. 5 Cells (JUs ll :lfllrilENti 32. 1 323.0 N1IC1I2O1I2N NlI-C1Iz-CH:NH: UH: ll.CnlluNo 40. 8 l0. 0

Table Continued Percentage of Empirical X Y Z formula N calcd. N found-s 0113 I H C13H13N5S 25.0 25.5

N /C2Hs CH3 CH3 Cl2Hl9N5 30. 30. 2 N\ C2I'I5 NHCH2-CH20H CH3 C2H5CnHnNgO 29. 8 29. 4 /C I i"3 CH: CaH Oi3Hg1N5O 26. 6 26.

CH2CH2-OH We claim: 4. The compound of claim 1 which is 1. A3-amino-1H-pyrazolo [3,4-b] pyridine of the formula (1113 Y I I j\HNHENHz CaH7NHLN N NH N N/ l i 5. The compound of claim 1 which is wherein Xis amino or alkylamino of 1 to 6 carbon atoms or E di-lower alkylammo,N112 Y 18 lower alkyl and Z is hydrogen. (CHM; N

3 \N N/ 2. The compound of claim 1 which 15 H l[ 6. The compound ofclaim 1 which is 40 N H2N N nfi on. 3 The com ound of claim 1 which isNR2 p CH: N CH3 I C2Hs H IF'NI'IE N I-IiCzNI-I

1. A 3-AMINO-LH-PYRAZOLO (3,4-B) PYRIDINE OF THE FORMULA
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